Method of cooling bicycle disc brake

ABSTRACT

A bicycle disc brake caliper is provided with a cooling system that transfers heat away from the actuating fluid. Basically, the bicycle disc brake caliper has a housing and a piston unit, with a coolant member of the cooling system attached to the housing. The housing has a frame mounting member sized to be coupled to a portion of a bicycle frame. The piston unit is movably coupled to the housing between a release position, in which the piston unit is spaced from a brake disc mounted to a wheel of a bicycle, and a braking position, in which the piston unit engages the brake disc of the bicycle wheel. The coolant member has a coolant area for receiving coolant to create a coolant heat sink that transfers heat from the housing. The housing has an actuating passage in fluid communication with the piston unit to move the piston unit via an actuating fluid. In one embodiment, the cooling system includes a pump and a reservoir. In another embodiment, a coolant or water bottle is attached to the coolant member for manually adding coolant thereto. In another embodiment, the coolant member is filled with a high specific heat gel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to a bicycle disc brake. Morespecifically, the present invention relates to a method of cooling abicycle disc brake via a cooling fluid.

2. Background Information

Bicycling is becoming an increasingly popular form of recreation as wellas a means of transportation. Moreover, bicycling has become a verypopular competitive sport. Whether the bicycle is used for recreation,transportation or competition, the bicycle industry is constantlyimproving their components. One particular component of the bicyclewhich has been extensively redesigned over the past years is the brakingsystems of bicycles.

There are several types of bicycle brake devices, which are currentlyavailable on the market. Examples of some types of common bicycle brakedevices include rim brakes, caliper brakes and disc brakes. If a riderwants a very high performance brake system, then the rider typicallywants a disc brake system. Disc brake systems provide a substantialbraking power in relationship to the amount of braking force applied tothe brake lever. Moreover, disc brake systems typically provide a highlevel of consistency in all types of weather and riding conditions.However, one problem with disc brakes is that the hydraulic or actuatingfluid can become overheated such that vapor-lock occurs. In other words,the heat generated by braking results in the hydraulic fluid increasingin volume so as to cause the brake pads to engage the brake disc evenwhen the brake lever is in the release position. When vapor-lock occurs,the bicycle wheels can lock up and throw the rider off of the bicycle.

In the prior art disc brake systems, several methods have been utilizedto avoid vapor-lock. For example, the caliper housing can be made largerto absorb more heat. Another method has been to make a larger brake discwith a wider surface area. Also, vapor-lock can be suppressed byutilizing high quality hydraulic fluid. Yet another method to avoidvapor-lock has been to use brake or friction pads which do not transferthe heat to the brake housing as readily as conventional friction pads.These prior art methods of avoiding vapor-lock have many problems. Oneparticular problem, is that these solutions often are expensive tomanufacture. Also, some of these prior art solutions are not completelyeffective.

In view of the above, there exists a need for a method of cooling abicycle disc brake which overcomes the above-mentioned problems in theprior art. This invention addresses these needs in the prior art as wellas other needs, which will become apparent to those skilled in the artfrom this disclosure.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a method of cooling abicycle disc brake with a coolant.

Another object of the present invention is to provide an improvedbicycle disc brake, which is reliable and durable.

In accordance with one aspect of the present invention, the method ofthe present invention is carried out by using a bicycle disc brakecaliper with a cooling member that transfers heat away from theactuating fluid. Basically, the bicycle disc brake caliper has ahousing, a piston unit and the coolant member. The coolant member can beeither an integral part of the caliper housing or a detachable member.The housing has a frame mounting member sized to be coupled to a portionof a bicycle frame. The piston unit is movably coupled to the housingbetween a release position, in which the piston unit is spaced from abrake disc mounted to a wheel of a bicycle, and a braking position, inwhich the piston unit engages the brake disc of the bicycle wheel. Thecoolant member is coupled to the housing. The coolant member has acoolant area for receiving coolant to create a coolant heat sink thattransfers heat from the housing. The housing has an actuating passage influid communication with the piston unit to move the piston unit via anactuating fluid.

The foregoing objects of the present invention can be attained byproviding the method of cooling a bicycle disc brake caliper whichselectively stops rotation of a bicycle wheel relative to a bicycleframe, comprising the steps of providing the bicycle wheel with a brakedisc fixedly coupled thereto for rotation therewith; providing thebicycle frame with a brake caliper including a housing and a piston unitmovably coupled to the housing to selectively engage the disc brake; andproviding the housing with a coolant member having an internal coolantarea for receiving coolant therein to create a coolant heat sink fortransferring heat from the housing.

In one embodiment, the cooling system includes a pump and a reservoir.In another embodiment, a coolant or water bottle is attached to thecoolant member for manually adding coolant thereto. In anotherembodiment, the coolant member is filled with a high specific heat gel.Yet in other embodiments, the coolant member is adjustable to beoriented with its outlet opening substantially perpendicular to theground.

Other objects, advantages and salient features of the present inventionwill become apparent to those skilled in the art from the followingdetailed description, which, taken in conjunction with the annexeddrawings discloses preferred embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a side elevational view of a portion of a bicycle with a fluidcooled bicycle disc brake assembly coupled thereto in accordance withone embodiment of the present invention;

FIG. 2 is a partial side elevational view of a portion of the front forkof the bicycle with the radiator, motor and pump of the cooling systemcoupled thereto in accordance with the embodiment of the presentinvention illustrated in FIG. 1;

FIG. 3 is a partial front elevational view of a portion of the frontfork of the bicycle with the radiator, motor and pump of the coolingsystem coupled thereto in accordance with the embodiment of the presentinvention illustrated in FIG. 1;

FIG. 4 is a partial cross-sectional view of the radiator, motor and pumpof the cooling system coupled to a portion of the front fork of thebicycle in accordance with the embodiment of the present inventionillustrated in FIG. 1;

FIG. 5 is a partial side elevational view of a portion of the fluidcooled bicycle disc brake assembly coupled to the front fork of thebicycle in accordance with the embodiment of the present inventionillustrated in FIG. 1;

FIG. 6 is a side elevational view of a bicycle disc brake caliper of thefluid cooled bicycle disc brake assembly in accordance with theembodiment of the present invention illustrated in FIG. 1;

FIG. 7 is an exploded front elevational view of the bicycle disc brakecaliper of the fluid cooled bicycle disc brake assembly in accordancewith the embodiment of the present invention illustrated in FIG. 1;

FIG. 8 is an inside elevational view of a first housing half of thebicycle disc brake caliper of the fluid cooled bicycle disc brakeassembly in accordance with the embodiment of the present inventionillustrated in FIG. 1;

FIG. 9 is an inside elevational view of a second housing half of thebicycle disc brake caliper of the fluid cooled bicycle disc brakeassembly in accordance with the embodiment of the present inventionillustrated in FIG. 1;

FIG. 10 is a top plan view of a bicycle brake operating device for thefluid cooled bicycle disc brake assembly in accordance with theembodiment of the present invention illustrated in FIG. 1;

FIG. 11 is a schematic diagram of the fluid cooled bicycle disc brakeassembly in accordance with the embodiment of the present inventionillustrated in FIG. 1;

FIG. 12 is an inside elevational view of a modified first housing halfof the bicycle disc brake caliper of the fluid cooled bicycle disc brakeassembly in accordance with another embodiment of the present invention;

FIG. 13 is an inside elevational view of a modified second housing halfof the bicycle disc brake caliper of the fluid cooled bicycle disc brakeassembly in accordance with the embodiment of the present inventionillustrated in FIG. 12;

FIG. 14 is a side elevational view of selected parts of a fluid cooledbicycle disc brake assembly in accordance with another embodiment of thepresent invention;

FIG. 15 is a side elevational view of a bicycle disc brake caliper witha closed coolant chamber or member in accordance with another embodimentof the present invention;

FIG. 16 is a side elevational view of a bicycle disc brake caliper witha refillable coolant chamber or member in accordance with anotherembodiment of the present invention;

FIG. 17 is a side elevational view of a bicycle disc brake caliper witha replaceable coolant chamber or member in accordance with anotherembodiment of the present invention;

FIG. 18 is a side elevational view of replaceable coolant chamber ormember illustrated in FIG. 17; and

FIG. 19 is a side elevational view of a bicycle disc brake caliper withan adjustable and replaceable coolant chamber or member in accordancewith another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, a front portion of a bicycle 10 isillustrated with a fluid cooled disc brake assembly 12 coupled theretoin accordance with one embodiment of the present invention. Bicyclessuch as bicycle 10 are well known in the art, and thus, bicycle 10 andits various components will not be discussed or illustrated in detailherein. It will be apparent to those skilled in the art that bicycle 10can be any type of bicycle, e.g., mountain bike, a hybrid bike or a roadbike. Bicycle 10 is a conventional bicycle, which basically includes abicycle frame 14 with a handle bar 15, front and rear forks 16 (onlyfront fork shown), front and rear wheels 17 (only front wheel shown) anda drive train (not shown).

While only the front portion of bicycle 10 is illustrated as having afluid cooled disc brake assembly 12, it will be apparent to thoseskilled in the art from this disclosure that a second fluid cooled discbrake assembly 12 can be utilized for stopping the rear wheel of bicycle10. Moreover, it will also be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be made fromthe embodiments disclosed herein without departing from the scope of theinvention as defined in the appended claims.

Fluid cooled disc brake assembly 12 basically includes a cooling system20, a disc brake caliper 21, a disc brake 22 and a brake operatingmechanism 23. Cooling system 20 is basically mounted on the front fork16 of bicycle 10. Likewise, disc brake caliper 21 is also mounted onfront fork 16 of bicycle 10 adjacent brake disc 22. Brake disc 22 isfixedly coupled to front wheel 17 for rotation therewith. Brakeoperating mechanism 23 is preferably fixedly mounted on handle bar 15adjacent the hand portion of handle bar 15. Accordingly, brake operatingmechanism 23 is operated such that disc brake caliper 21 moves from arelease position in which bicycle wheel 17 and brake disc 22 are free torotate, and a braking position in which disc brake caliper 21 applies abraking force against brake disc 22 to stop rotation of bicycle wheel 17and brake disc 22. Cooling system 20 is preferably designed to preventvapor lock from occurring within disc brake caliper 21. Specifically,cooling system 20 is preferably designed to act as a coolant heat sinkthat transfers heat from disc brake caliper 21.

Turning now to FIGS. 3-6, a portion of cooling system 20 is illustratedin more detail. Cooling system 20 basically includes a coolant member 24(FIG. 6), pump 25 and radiator 26. In this embodiment, coolant member 24is a detachable and replaceable member, which is fixedly coupled to discbrake caliper 21 to create a coolant heat sink which transfers heat awayfrom disc brake caliper 21 as explained below in more detail. Of course,it will be apparent to those skilled in the art from this disclosurethat coolant member 24 integrally formed with a portion of disc brakecaliper 21 to create a coolant heat sink which transfers heat away fromdisc brake caliper 21. Coolant member 24 will be discussed in moredetail below together with the description of disc brake caliper 21.

Preferably, pump 25 and radiator 26 are mounted to front fork 16 ofbicycle 10 by a mounting bracket assembly. The mounting bracket assemblyincludes a cross-strap 28 a and a pair of intermediate straps 28 b and28 c. Accordingly, pump 25 and radiator 26 are mounted as a compact uniton fork 16.

Pump 25 is preferably a rotary pump which moves coolant through coolantmember 24 and radiator 26. In particular, as seen in FIGS. 3-6, a firstflexible conduit 30 a extends from coolant member 24 to an inlet opening32 a of radiator 26, a second flexible conduit 30 b extends from anoutlet opening 32 b of radiator 26 to an inlet opening 34 a of pump 25,and a third flexible tubing 30 c extends from an outlet 34 b of pump 25to coolant member 24. Accordingly, conduits 30 a, 30 b and 30 c form acontinuous loop or conduit path between coolant member 24, pump 25 andradiator 26. Coolant is forced through the conduit path by pump 25 forremoving heat from coolant member 24 and disc brake caliper 21.

As best shown in FIG. 4, pump 25 is preferably operated by a motor 36which rotates an impeller 38 to force fluid for coolant through pump 25.Motor 36 in the preferred embodiment is an electric motor that isbattery operated. More specifically, two conventional batteries 40 areutilized to power motor 36. A three-positioned switch 42 is provided forcontrolling the operation of motor 36. Specifically, switch 42 has acentral off position, an on position and a sensor position. In the offposition, motor 36 is idle, and thus, pump 25 is not operated. In the onposition, motor 36 turns impeller 38 of pump 25 to force fluid orcoolant through the conduit path of cooling system 20. The sensorposition operates motor 36 based on the temperature of the coolant ordisc brake caliper 21. In particular, as seen in FIG. 6, a sensor 44 ismounted to disc brake caliper 21 to determine the temperature of eitherthe coolant or the housing of disc brake caliper 21. Accordingly, switch42 and motor 36 are electrically coupled to sensor 44 such that motor 36only operates when the temperature of the coolant and/or housing of discbrake caliper 21 reaches a predetermined temperature level, e.g.,greater than 80° C. Once the coolant or disc brake caliper 21 reachesthis predetermined temperature level, motor 36 will operate to turnimpeller 38 for pumping coolant or fluid through coolant member 24 andradiator 26 to reduce the temperature of caliper 21.

It will be apparent to those skilled in the art that other types ofpumping systems, motors and temperature sensors can be utilized in thecooling system 20 of the present invention. For example, a pump can beused in which the pump is operated by rotating parts of the bicycle 10.Moreover, pumps, motors and sensors such as pump 25, motor 36 and sensor44 are well known in the prior art. Thus, these parts will not bedescribed or illustrated in detail.

Radiator 26 is preferably a conventional type of radiator, whichincludes a conduit path with a large surface area so as to beair-cooled. Since radiator 26 is relatively conventional inconstruction, radiator 26 will not be described or illustrated in detailherein.

It will be apparent to those skilled in the art that pump 25 and/orradiator 26 can be eliminated. For example, the conduit path can be setup as a “coffee percolator” such that the coolant is self-circulatingthrough coolant member 24.

Turning now to FIGS. 5-9, disc brake caliper 21 will now be described inmore detail. Disc brake caliper 21 is fixedly coupled to fork 16adjacent to brake disc 22 for applying a clamping force to stop therotation of bicycle wheel 17 and brake disc 22. Disc brake caliper 21basically includes a housing 50, a piston unit 51 and coolant member 24which is fixedly coupled thereto via fastening means such as adhesive,straps, bolts, rivets or other fasteners. Coolant member 24 ispreferably constructed two halves, which are fixedly secured together.

Disc brake caliper 21 is basically a conventional disc brake caliperexcept that cooling system 20 has been coupled to it for removing heattherefrom. More specifically, except for the addition of coolant member24 to disc brake caliper 21, the structure and function of disc brakecaliper 21 is relatively conventional. Therefore, disc brake caliper 21will not be discussed or illustrated in detail herein.

As seen in FIGS. 7-9, housing 50 is preferably constructed of a heatconductive material, which can readily transfer the heat to the coolant.For example, housing 50 can be constructed of aluminum. Housing 50includes a first housing half 52 a and a second housing half 52 b whichare bolted together in a conventional manner. For all practicalpurposes, first and second housing halves 52 a and 52 b aresubstantially identical in construction, except that second housing half52 b has brake operating mechanism 23 attached thereto for supplying anactuating fluid to first and second housing halves 52 a and 52 b. Also,second housing half 52 b has a pair of outwardly extending flanges thatform a mounting member 54 for bolting disc brake caliper 21 to fork 16of bicycle 10. When housing halves 52 a and 52 b are bolted together, adisc brake slot is formed therebetween for receiving brake disc 22therebetween.

As seen in FIGS. 8 and 9, first housing half 52 a has a pair of circularpiston recesses 57 a and an internal fluid actuating passage 58 a.Likewise, second housing half 52 b has a pair of piston receivingrecesses 57 b and an internal fluid actuating passage 58 b. A first halfof coolant member 24 is coupled to the first housing half 52 a, while asecond half of coolant member 24 is coupled to the second housing half52 b. The first half of coolant member 24 has a coolant cavity or area56 a, while a second half of coolant member 24 has a coolant cavity orarea 56 b. Cavities or areas 56 a and 56 b form a large coolant chamber.Preferably, coolant member 24 can hold at least approximately ten cubiccentimeters to approximately twenty cubic centimeters.

The first half of coolant member 24 has an inlet opening 60 and anoutlet opening 62. Inlet opening 60 is preferably a threaded hole, whichreceives a connector 64 to connect conduit 30 c thereto. Outlet opening62 is also preferably a threaded bore having an outlet connector 66coupled thereto to connect conduit 30 a thereto. Connectors 64 and 66are preferably provided with one-way valves or check valves that allowthe fluid or coolant to pass into coolant cavities 56 a and 56 b throughinlet opening 60 and out of coolant cavities 56 a and 56 b via outletopening 62.

Internal fluid actuating passage 58 a extends between circular pistonrecesses 57 a and internal fluid actuating passage 58 b of secondhousing half 52 b. In other words, the actuating fluid from brakeoperating mechanism 23 flows into second housing half 52 b and then intointernal fluid actuating passages 58 a and 58 b to operate piston unit51.

Second housing half 52 b has a first threaded opening 68, which is influid communication with internal fluid actuating passage 58 b. Opening68 is designed for attaching a hydraulic or actuating fluid conduitthereto. A second opening 70 is also provided for threadedly receiving ableed nipple 72. Opening 70 is in fluid communication with internalfluid actuating passage 58 b such that excess air can be removed fromthe actuating system. Internal fluid actuating passage 58 binterconnects piston recesses 57 b together for receiving actuatingfluid or hydraulic fluid to activate piston unit 51.

As seen in FIG. 7, piston unit 51 preferably includes four pistons 74and a pair of friction pads 76. Pistons 74 are slidably received inpiston recesses 57 a and 57 b for movement between a release positionand a braking position. Friction pads 76 are located on the free ends ofpistons 74 for movement therewith. In other words, as pistons 74 movefrom a release position to a braking position, friction pads 76 alsomove from a release position to a braking position. In the brakingposition, friction pads 76 frictionally engage brake disc 22 to stop therotation of brake disc 22 and wheel 17. In the release position,friction pads 76 are spaced from brake disc 22 to allow brake disc 22and wheel 17 to freely rotate therebetween. Pistons 74 and friction pads76 are moved from their release positions to their braking positions byactuating or hydraulic fluid applying a force to pistons 74. Morespecifically, as brake operating mechanism 23 is actuated, actuatingfluid is pressurized so as to force pistons 74 and friction pads 76toward brake disc 22.

When brake caliper 21 is coupled to front fork 16, coolant member 24 ispositioned on the downstream end of the disc brake caliper 21. In otherwords, as seen in FIG. 1, brake disc 22 rotates in a counterclockwisedirection such that the coolant member 24 is positioned downstream ondisc brake caliper 21 in relationship to the rotational direction ofbrake disc 22. This allows the heat to be removed from the downstreamend of brake caliper 21 more quickly since this is the area in which theactuating fluid is being supplied and the area of increased heat.

Referring now to FIGS. 10 and 11, brake operating mechanism 23 will nowbe described in more detail. Basically, brake operating mechanism 23 isdesigned to actuate the disc brake caliper 21 to apply a forciblegripping action on brake disc 22 to stop rotation of front wheel 17.Brake operating mechanism 23 basically includes a brake lever 80, ahydraulic or master cylinder 81, a hydraulic or master piston 82, and anactuation fluid reservoir 83.

Preferably, brake operating mechanism 23 is a single unit which ismounted on handlebar 15. In particular, brake lever 80 includes amounting portion 84 and a lever portion 85. Mounting portion 84 isdesigned to be clamped onto handle bar 15 in a conventional manner.Mounting portion 84 is integrally formed with master cylinder 81 suchthat master cylinder 81, master piston 82 and actuation fluid reservoir83 are all supported on mounting portion 84 of brake lever 80. Leverportion 85 is pivotally coupled to mounting portion 84 for movementbetween a release position and a braking position. Normally, leverportion 85 is maintained in a release position in a conventional manner.

Master piston 82 is movably mounted within master cylinder 81 in aconventional manner. More specifically, actuation fluid reservoir 83 ismounted on master cylinder 81 and in fluid communication with theinterior bore of master cylinder 81 for supplying actuation fluidthereto. Master piston 82 is connected at one end to lever portion 85for axially moving master piston 82 within master cylinder 81.Accordingly, actuation of lever portion 85 causes master piston 82 tomove axially within master cylinder 81. This movement of master piston82 within master cylinder 81 directs fluid pressure through a hydraulicline 86 which is coupled to disc brake caliper 21. Thus, the pressurizedactuation fluid causes the pistons 74 and friction pads 76 to move so asto engage brake disc 22 to stop rotation of wheel 17.

Second Embodiment

Referring now to FIGS. 12 and 13, a modified disc brake caliper 121 isillustrated in accordance with the present invention. Disc brake caliper121 is designed to be utilized in fluid cooled disc brake assembly 12,discussed above. In fact, disc brake caliper 121 is substantiallyidentical to disc brake caliper 21 except that disc brake caliper 121has its cooling cavities or areas 156 a and 156 b provided with aninternal conduit path and coolant member 124 is integrally formed with aportion of disc brake caliper 121. Of course, it will be apparent tothose skilled in the art from this disclosure that coolant member 124can be a separable member which is fixedly coupled to disc brake caliper121 to create a coolant heat sink which transfers heat away from discbrake caliper 121. More specifically, baffles 156 c and 156 d are formedwithin coolant cavities or areas 156 a and 156 b, respectively. In viewof the similarities between disc brake caliper 21 and 121, disc brakecaliper 121 and its connection to cooling system 20 will not bediscussed or illustrated in detail herein.

Housing 150 is preferably constructed of a heat conductive material,which can readily transfer the heat to the coolant. For example, housing150 can be constructed of aluminum. Housing 150 includes a first housinghalf 152 a and a second housing half 152 b which are bolted together ina conventional manner. For all practical purposes, first and secondhousing halves 152 a and 152 b are substantially identical inconstruction, except that housing half 152 a has coolant system 20attached thereto, and second housing half 152 b has brake operatingmechanism 23 attached thereto for supplying an actuating fluid to firstand second housing halves 152 a and 152 b. Also, second housing half 152b has a pair of outwardly extending flanges that form a mounting member154 for bolting disc brake caliper 121 to fork 16 of bicycle 10. Whenhousing halves 152 a and 152 b are bolted together, a disc brake slot isformed therebetween for receiving brake disc 22 therebetween.

First housing half 152 a has a coolant cavity or area 156 a, a pair ofcircular piston recesses 157 a and an internal fluid actuating passage158 a. Likewise, second housing half 152 b has a coolant cavity or area156 b, a pair of piston receiving recesses 157 b and an internal fluidactuating passage 158 b. Cavities or areas 156 a and 156 b form a largecoolant chamber. Preferably, coolant member 124 can hold at leastapproximately ten cubic centimeters to approximately twenty cubiccentimeters.

Coolant cavity or area 156 a is a large chamber having an inlet opening160 and an outlet opening 162. Inlet opening 160 is preferably athreaded hole, which receives a connector 164 to connect conduit 30 cthereto. Outlet opening 162 is also preferably a threaded bore having anoutlet connector 166 coupled thereto to connect conduit 30 a thereto.Connectors 164 and 166 are preferably provided with one-way valves orcheck valves that allow the fluid or coolant to pass into coolantcavities 156 a and 156 b through inlet opening 160 and out of coolantcavities 156 a and 156 b via outlet opening 162.

Internal fluid actuating passage 158 a extends between circular pistonrecesses 157 a and internal fluid actuating passage 158 b of secondhousing half 152 b. In other words, the actuating fluid from brakeoperating mechanism 23 flows into second housing half 152 b and theninto internal fluid actuating passages 158 a and 158 b to operate thepiston unit.

Second housing half 152 b has a first threaded opening 168, which is influid communication with internal fluid actuating passage 158 b. Opening168 is designed for attaching a hydraulic or actuating fluid conduitthereto. A second opening 170 is also provided for threadedly receivinga bleed nipple 172. Opening 170 is in fluid communication with internalfluid actuating passage 158 b such that excess air can be removed fromthe actuating system. Internal fluid actuating passage 158 binterconnects piston recesses 157 b together for receiving actuatingfluid or hydraulic fluid to activate the piston unit.

Third Embodiment

Referring now to FIG. 14, a simplified cooling system 220. Basically,cooling system 220 includes coolant member 224, coolant bottle or tank226, an on/off valve 227 and a pressure release valve 228. Disc brakecaliper 221 is substantially identical to disc brake caliper 21discussed above, except that a coolant gauge 229 has been added to theintegral coolant member 224 to visually inspect the amount of coolant orwater contained within coolant member 224.

In view of the similarities between disc brake caliper 221 and discbrake caliper 21 of the first embodiment, disc brake caliper 221 willnot be discussed or illustrated in detail herein. Moreover, it will beapparent to those skilled in the art from this disclosure that discbrake caliper 221 can be utilized on bicycle 10 of the first embodimentso as to be operated by brake operating mechanism 23 of the firstembodiment to engage brake disc 22.

In this embodiment, cooling system 220 is designed such that the ridercan manually add water or coolant periodically to coolant member 224.More specifically, the water or coolant within coolant member 224 willbe heated when the friction pads engage brake disc 22. The heated wateror coolant will turn into steam or coolant vapor if the brake disccaliper 221 gets too hot. This steam will open pressure release valve228 such that the water or coolant vapor is released. Thus, the amountof coolant within coolant member 224 will gradually be reduced. Therider then can look at coolant gauge 229 to determine when coolant needsto be added. The rider will then open the on/off valve 227 to allowadditional water of coolant from coolant bottle 226 to flow throughconduit 230 into coolant member 224.

Water or coolant bottle 226 can be attached to any portion of the frameas needed and/or desired. For example, water bottle 226 can be attachedto the front fork 16 of bicycle 10 in the same location as radiator 26of the first embodiment of FIG. 1. Preferably, the location of waterbottle 226 is such that the rider can operate on/off valve 227 withoutstopping. Moreover, water bottle 226, valve 227 and conduit 230 arepreferably easily detachable from coolant member 224 such that they canbe replaced if damaged. A one-way valve 264 preferably connects conduit230 to the inlet opening of coolant member 224.

Fourth Embodiment

As seen in FIG. 15, a modified disc brake caliper 321 is illustrated.Disc brake caliper 321 is substantially identical to disc brake caliper21 of the first embodiment except that the internal coolant member 324is a closed unit, which has a high specific heat gel located therein.While coolant member 324 is illustrated as being detachable, it will beapparent to those skilled in the art from this disclosure that coolantmember 324 can be made integral with housing 350. Thus, this system is asimplified version of the first embodiment. The high specific heat gellocated in coolant member 324 can be any high specific heat gel, whichcan operate under the normal operating conditions of a bicycle discbrake.

In view of the similarities between disc brake caliper 321 and discbrake caliper 21 of the first embodiment, disc brake caliper 321 willnot be discussed or illustrated in detail herein. Moreover, it will beapparent to those skilled in the art from this disclosure that discbrake caliper 321 can be utilized on bicycle 10 of the first embodimentso as to be operated by brake operating mechanism 23 of the firstembodiment to engage brake disc 22.

Fifth Embodiment

Referring now to FIG. 16, a modified disc brake caliper 421 isillustrated in accordance with the present invention. In thisembodiment, the coolant inlet opening 460 and coolant outlet opening 462are interconnected together via a transparent conduit 430. Thistransparent conduit 430 allows the rider to inspect the coolant levelwithin the coolant member 424. Also, a pressure release valve/refillvalve 428 has been added such that additional coolant or fluid can beadded as needed and/or steam or coolant vapor be released from thecoolant member 424.

Disc brake caliper 421 is substantially identical to disc brake caliper21 except that disc brake caliper 421 has transparent conduit 430extending between its inlet opening 460 and coolant outlet opening 462and pressure release valve/refill valve 428 has been added. In view ofthe similarities between disc brake caliper 421 and disc brake caliper21 of the first embodiment, brake disc caliper 421 will not be discussedor illustrated in detail herein.

In this embodiment, cooling system 420 is designed such that the ridercan manually add water or coolant periodically to coolant member 424 viapressure release valve/refill valve 428. More specifically, the water orcoolant within coolant member 424 will be heated when the friction padsengage brake disc 22. The heated water or coolant will turn into steamor coolant vapor if the disc brake caliper 421 gets too hot. This steamwill open pressure release valve/refill valve 428 such that the water orcoolant vapor is released. Thus, the amount of coolant within coolantmember 424 will gradually be reduced. The rider then can look attransparent conduit 430 to determine when coolant needs to be added. Therider will then add additional water of coolant to coolant member 424via pressure release valve/refill valve 428.

Sixth Embodiment

Referring now to FIGS. 17 and 18, a modified disc brake caliper 521 isillustrated in accordance with the present invention. In embodiment, adetachable and replaceable cooling system or unit 520 is fixedlyattached to the disc brake caliper 521. Cooling system or unit 520includes a mounting member 555 with a piping system 556 fixedly securedthereto. Piping system 556 forms the coolant member 524.

Mounting member 555 is shaped for mounting on housing 550 of disc brakecaliper 521. Mounting member 555 can be secured to housing 550 in avariety of ways. For example, mounting plate 550 can be fastened tohousing 550 via adhesive, straps, bolts, rivets or any other suitablefasteners. In any event, mounting member 555 contacts housing 550 suchthat heat can be readily transferred from housing 550 to mounting member555 which in turn transfers the heat to piping system 556. The coolantpassing through, piping system 556 removes the heat from housing 550,mounting member 555 and piping system 556. In this embodiment, pipingsystem 556 has an inlet opening 560 and an outlet opening 562.

The piping system 556 is looped back and forth between inlet opening 560and outlet opening 562 to create a coolant chamber 524 therebetween.Inlet opening 560 is connected to an external conduit path via conduit30 b, while outlet opening 562 is connected to an external conduit pathvia conduit 30 a. Conduits 30 a and 30 b can be coupled to inlet andoutlet openings 560 and 562 by one-way valves in the same manner as inthe first embodiment, if needed and/or desired.

Cooling system or unit 520 can be used with the pump 25 and/or radiator26 of the first embodiment as needed and/or desired. Alternatively, itwill be apparent to those skilled in the art from this disclosure thatpump 25 and/or radiator 26 can be eliminated. For example, the conduitpath can be set up as a “coffee percolator” such that the coolant isself-circulating through coolant member 524. Cooling system or unit 520is especially adapted for use as a self-circulating system in that theoutlet opening 562 is located higher than the inlet opening 560. Thisarrangement allows the coolant to percolate through coolant member 524.

Disc brake caliper 521 is substantially identical to disc brake caliper21 of the first embodiment except that the internal coolant member 24 ofthe first embodiment has been replaced with an external cooling systemor unit 520. In view of the similarities between disc brake caliper 521and disc brake caliper 21 of the first embodiment, disc brake caliper521 will not be discussed or illustrated in detail herein. Moreover,brake operating mechanism 23 or the first embodiment is designed to beattached to housing 550 for supplying an actuating fluid to the firstand second halves of housing 550 in substantially the same manner as inthe first embodiment. In other words, conduit 86 of the brake operatingmechanism 23 is attached to the housing 550 in a conventional manner tosupply actuating fluid thereto for selectively gripping brake disc 22.

Seventh Embodiment

Referring now to FIG. 19, a modified disc brake caliper 621 isillustrated in accordance with the present invention. In thisembodiment, a detachable and replaceable cooling system or unit 620 isfixedly attached to the disc brake caliper 621. Cooling system or unit620 includes a mounting member or an attachment portion 655 and anelongated coolant portion or member 624. Cooling system or unit 620 isadjustably mounted to housing 650 via a mounting bolt 670. Preferably,coolant member 624 is normally adjusted to be oriented in asubstantially vertical direction relative to the ground. In particular,the mounting member 655 is a flange with a hole for receiving bolt 670therethrough to adjustably secure coolant member 624 thereto.

As seen in FIG. 19, coolant member 624 has an internal coolant area 656,a lower inlet opening 660 and an upper outlet opening 662. In thisembodiment, internal coolant area 656 of coolant member 624 has aplurality of internal baffles 657. The lower inlet opening 660 islocated at a first longitudinal end of coolant member 624, while theupper outlet opening 662 is located at a second longitudinal end ofcoolant member 624. Inlet opening 660 is connected to an externalconduit path via conduit 30 b, while outlet opening 662 is connected toan external conduit path via conduit 30 a. Conduits 30 a and 30 b can becoupled to inlet and outlet openings 660 and 662 by one-way valves inthe same manner as in the first embodiment, if needed and/or desired.

As mentioned above, coolant member 624 is angularly adjustable relativeto the bicycle disc brake caliper 621 to position its outlet opening 662substantially perpendicular relative to ground, when attachment portion655 is coupled to bicycle disc brake caliper 621. Cooling system or unit620 can be used with pump 25 and/or radiator 26 of the first embodimentas needed/desired. Alternatively, it will be apparent to those skilledin the art from this disclosure that pump 25 and/or radiator 26 can beeliminated. For example, this design is especially useful in creating aconduit path that can be set up as a “coffee percolator” such that thecoolant is self-circulating through coolant member 624. Cooling systemor unit 620 is especially adapted for use as a self-circulating systemin that the outlet opening 662 is located higher than the inlet opening660. This arrangement allows the coolant to percolate through coolantmember 624.

Disc brake caliper 621 is substantially identical to disc brake caliper21 of the first embodiment except that the internal coolant member 24 ofthe first embodiment has been replaced with an external cooling systemor unit 620. In view of the similarities between disc brake caliper 621and disc brake caliper 21 of the first embodiment, disc brake caliper621 will not be discussed or illustrated in detail herein. Moreover,brake operating mechanism 23 or the first embodiment is designed to beattached to housing 650 for supplying an actuating fluid to the firstand second halves of housing 650 in substantially the same manner as inthe first embodiment. In other words, conduit 86 of the brake operatingmechanism 23 is attached to the housing 650 in a conventional manner tosupply actuating fluid thereto for selectively gripping brake disc 22.

While several embodiments have been chosen to illustrate the presentinvention, it will be apparent to those skilled in the art from thisdisclosure that various changes and modifications can be made hereinwithout departing from the scope of the invention as defined in theappended claims. Furthermore, the foregoing description of the preferredembodiments of the present invention is provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

What is claimed is:
 1. A method of cooling a bicycle disc brake caliperwhich selectively stops rotation of a bicycle wheel relative to abicycle frame, comprising the steps of: rotating said bicycle wheel witha brake disc fixedly coupled thereto for rotation therewith; operating abrake caliper including a housing and a piston unit movably coupled tosaid housing to selectively engage said disc brake; cooling said housingby providing coolant in a coolant member having an internal coolant areafor receiving coolant therein to create a coolant heat sink fortransferring heat from said housing; and said cooling of said housingoccurring solely at a downstream end of a disc receiving slot extendingthrough said housing adjacent said piston unit to receive the brake disctherein, such that the brake disc rotates from an upstream end of saidslot to said downstream end of said slot.
 2. A method of cooling abicycle disc brake caliper according to claim 1, further comprising thestep of circulating coolant through a radiator mounted on a portion ofthe bicycle and fluidly coupling said radiator to said coolant area tocirculate coolant through said coolant area.
 3. A method of cooling abicycle disc brake caliper according to claim 1, further comprising thestep of providing a brake operating device which is located to beoperated from a handle bar of said bicycle.
 4. A method of cooling abicycle disc brake caliper according to claim 1, further comprising thestep of providing said coolant member with a first opening and a secondopening with an external conduit path extending therebetween.
 5. Amethod of cooling a bicycle disc brake caliper according to claim 4,further comprising the step of providing said external conduit path witha radiator to dissipate heat from coolant passing therethrough.
 6. Amethod of cooling a bicycle disc brake caliper according to claim 5,further comprising the step of providing said external conduit path witha pump for circulating coolant through said coolant chamber and saidradiator.
 7. A method of cooling a bicycle disc brake caliper accordingto claim 6, further comprising the step of driving said pump via anelectric motor.
 8. A method of cooling a bicycle disc brake caliperaccording to claim 7, further comprising the step of powering saidelectric motor by at least one battery.
 9. A method of cooling a bicycledisc brake caliper according to claim 4, further comprising the step ofmoving coolant through said coolant area and said external conduit pathby a pump.
 10. A method of cooling a bicycle disc brake caliperaccording to claim 9, further comprising the step of controlling saidpump with a switch for selectively activating and deactivating saidpump.
 11. A method of cooling a bicycle disc brake caliper according toclaim 9, further comprising the step of controlling said pump with atemperature sensor mounted to said heat conductive housing for at leastpartially activating and deactivating said pump.
 12. A method of coolinga bicycle disc brake caliper according to claim 1, further comprisingthe step of providing said piston unit with at least first and secondpistons.
 13. A method of cooling a bicycle disc brake caliper accordingto claim 1, further comprising the step of providing said coolant memberwith an inlet opening with a one-way valve and an outlet opening with apressure release valve.
 14. A method of cooling a bicycle disc brakecaliper according to claim 1, further comprising the step of providingsaid bicycle frame with an actuating fluid system which selectivelymoves at least one portion of said piston unit between a releaseposition in which said piston unit is spaced from a brake disc mountedto said bicycle wheel and a braking position in which said piston unitengages said brake disc of said bicycle wheel.
 15. A method of cooling abicycle disc brake caliper which selectively stops rotation of a bicyclewheel relative to a bicycle frame, comprising the step of rotating saidbicycle wheel with a brake disc fixedly coupled thereto for rotationtherewith; operating brake caliper including a housing and a piston unitmovably coupled to said housing to selectively engage said disc brake;cooling said housing by providing coolant in a coolant member having aninternal coolant area for receiving coolant therein to create a coolantheat sink for transferring heat from said housing; circulating coolantthrough said coolant member via a pump connected to a first opening anda second opening with an external conduit path extending therebetween;providing said external conduit path with a pump for circulating coolantthrough said coolant chamber and said radiator; and selectivelycontrolling said pump with a three position switch for selecting betweenan always on position, a temperature sensing position and an offposition.
 16. A method of cooling a bicycle disc brake caliper whichselectively stops rotation of a bicycle wheel relative to a bicycleframe, comprising the steps of: rotating said bicycle wheel with a brakedisc fixedly coupled thereto for rotation therewith; operating a brakecaliper including a housing and a piston unit movable coupled to saidhousing to selectively engage said disc brake; cooling said housing bycoolant in a coolant member having an internal coolant area forreceiving coolant therein to create a coolant heat sink for transferringheat from said housing; and said cooling of said housing occurring in asingle large coolant chamber defined by a first housing half having afirst portion of said cooling area formed therein and a second housinghalf having a second portion of said cooling area formed therein, saidfirst and second portions of cooling area having substantially equalsize openings joined together to form said single large coolant chamber.